Signaling system



Feb. 12, 1935.

J. B. SHIEL ET AL SIGNALING SYSTEM Original Filed Jan. 6, 1950 MARG/NALJ. asH/a A T TORNE'V Patented Feb. 12, 1935 UNITED STATES;

PATENT OFFICE 1,990,569 SIGNALING SYSTEM John B. Shiel, GlenHead, andAlbert G. Lang, Whitestone,N. .Y., assignors to Bell TelephoneLaboratories, Incorporated, New York, N, Y., a

corporation of New York :Original application January 6', 1930. SerialNo. 418,893. Divided and this application November 21,1930, Serial No.497,133

2 claims. (or. 177 3521 This in'vention relates to signaling systemswherein signaling circuits are controlled by an interrupter and moreparticularly to means asso' ciated with the interrupter connectingcircuitto 5 cause analarm to'be given and an emergency arrangementbrought into service to control the signaling circuitswhen an abnormalor unstandardi condition exists on the connecting circuit.

- This application is a division of abandoned; ap-

plication SerialNo. 418,893, filed January 6,1930

forimprovements insignaling systems.

In" accordance with the feature of the invention the interrupter isnormally connected to a. dis-'- tributing circuit which in turn isbranched out to anumber of signaling circuits or loadfcircuits requiredto be intermittently grounded through a corresponding plurality ofcontact pairs. When an abnormal or ,unstandard condition arises thenormal connection between the interrupter and the distributing circuitis broken and p the emergency arrangement is brought into play; Theemergency arrangement controls each line individually by means of saidcontact pairs thereby achieving the same result as the 'normalinterruptercircuit in a different manner; Through this arrangement,'anabnormal condition present on a particular signaling circuit whichbefore'the' switching takes place would be communicated to pulses fiowthrough the back contact and armature of relay 3 to conductorf i heretermed the distr-ibuting circuit. 'Ihec distributing circuit is iconnected-through the 1 armatures and back contacts of a plurality ofrelays5, 6 and 'Tto a plurality ofv occasionally energized signalingcircuits such-.as.8,i9' and 10. Circuits 8, 9 and 10 may be :anycircuits which are required to be intermittently grounded. Such circuitsare well known in the art as, for example; seethe patent to Potter1,479,555, issued January 1, 1924, which shows interrupter leads Iwhichcorrespond to the V 7' leads 8, 9, etc. of the present application.

The interrupter circuit 2 is connected through the normal contacts of akey 11 to the winding of a relay'12. This relayresponds'to theinterruptions and constantly vibrates its armature. If

the impulses supplied by the interrupter are at the rateof-40 or 60interruptions per minute, then the armature of relay '12 will bemovedbetween its frontand-its back contact at the rate of lfl or 60 times perminute; 1,

During the periods that the armature of relay 12 is resting on its frontcontact, a' circuit is closed forrelay l3 and this relay being slow torelease maintainsits armature in its operated position so long as relay12 is constantly operating as described.

' In the same manner, when the armature of relay 12 is resting on itsback contact a relay-141s energized and this also being slow to"release, maintains its armature inits operated position so;

long as relay 12 is constantly operating.

Through the constant energization of relays 13 and 14', a circuit isclosed for relay .15 and this being slow to release will maintain itsarmature: operated even though relays l3 and 14 should mo:-

mentarily release.

The conditions above described are normal and.

will be maintained so long as interrupterloperates properly and thecircuit 2 is maintained in a standard condition;

Let, it be assumed that conductor 2 becomesopened near the interrupter lor at any place between interrupter 1 and key 11;. then relay 12 willcease to operate and its armature will rest steadily on' its backcontact. Undertheseconditions relay. 14 will be maintained energized butin a short interval relay 13 will become deenergized. Thereupon thecircuit for relay 15 will be opened and this relay will allow. itsarmature to return to normal. The result'of this will be described indetail hereinafter.

Let it now be assumed that the conductor 2' becomes grounded. In thatcase, relay 12. will become steadily operated and its armature will.rest constantly on its front contact. Under these.

conditions relay 13 will bev maintained energized, but relay 14willrelease, and after a short,

interval as before, relay 15 will return its armature to normal.

' The-grounding of conductor 2 may take place. either on the conductor,2 itself, on the distributing circuit 4, or on any one of the signalingcircuits such as 8, 9 or 10.

It should be particularly noted that in the case,

where one of the signaling circuits such as 8 becomes permanentlygrounded, that this ground.

under these normal conditions will be communicated to all the othersignaling circuits such as 9 and 10 and will therefore put them out ofcommission, It should be further noted that relay 12 may be heldoperated by a ground through aresistance so that by proper design, relay12 may be made to respond to any ground condition on a signaling circuitwhich would tend to disrupt the service.

It will thus be seen that when either the interrupter circuit 2 isopened between the interrupter 1 and the key 11, or such circuit isgrounded, that relay 15 will return to normal.

Upon this occurrence, a circuit will be established from ground, thearmature and back contact of relay 15, winding of relay 16 to battery.Relay 16 becomes energized and locks in a circuit from ground, key 17,front contact and lefthand armature of relay 16, winding of relay 16 tobattery. Through the operation of its righthand armatures, relay 16first closes a circuit from ground the innermost right-hand armature andfront contact of relay 16, alarm 18 to battery. At the same time acircuit is closed from ground, outermost armature and front contact ofrelay 16, winding of relay 3 to battery. Relay 3 becomes operated anddisconnects the interrupter circuit 2 from the distributing circuit 4and permanently grounds the distributing circuit over the front contactof-relay 3.

Thus, upon interruption of the service over interrupter circuit 2, alarm18 is operated and the, distributing circuit 4 is permanently grounded.

At the same time the ground for operating relay 16 is communicated tothe visual alarm 19 and this operates steadily. v 7

Through its middle right-hand armature, relay 16 places a ground onconductor '20. This ground finds ,a circuit through relay 21 andresistance 22 to battery whereupon relay 21 becomes oper ated. Upon theoperation of relay 21 a shortcircuit about the winding of relay 23 isopened and this relay now becomes operated in series with resistance 24.In the same manner, upon the operation of relay 23, a short-circuitabout the winding of relay 25 is opened and this relay in turn becomesoperated in series with resistance 26. Relay 25 in operating now closesa shortcircuit about the winding of relay 21 and after a short intervalrelay 21 becomes deenergized. When relay 21 returns to normal, it inturn shortcircuits relay 23 and relay 23 in turn short-circuits relay25. This cycle of operations occurs periodically.

Upon the first operation of relay 25, a circuit is closed from ground,the outer right-hand armature and front contact of relay 25, theleft-hand armature and back contact of relay 27, winding of relay 28,left-hand winding of relay 27 to battery. Relay 28 operates in thiscircuit but relay 27, being marginal, fails to operate. Upon theoperation of relay 28, a circuit to the right-hand winding of relay 27is closed but this only results in short-circuiting such winding, sincea ground is to be found on conductor 20 which is communicated throughthe armature and front contact of relay 28 to one side of the right-handwinding of relay 27, the other side being grounded through theouterright-hand armature of relay 25.

Upon the following release of relay 25, the short-circuit about theright-hand winding of relay 27 is removed and now relay 2'7 becomesoperated in a circuit from ground, the middle right-hand armature andfront contact of relay 16, conductor 20, armature and front contact ofrelay 28, right-hand winding of relay 27, winding of relay 28, left-handwinding of relay 27 to battery. Relay 27 now operates its armatures andprepares acircuit wherein relay 28 will become deenergized. As soon asrelay 25 again becomes operated, a ground is connected directly to theleft-hand winding of relay 27 and the Winding of relay 28 and theright-hand winding of relay 27 in series therewith are short-circuited.Relay 28 becomes deenergized and relay 27 holds.

Upon the next deenergization of relay 25, relay 2''! releases.

Thus it will be seen that for each two complete cycles of operation ofrelay 25, relay 27 will go through one complete cycle of operations.

Upon'each energization of relay 27 a circuit is closed for relay 29.This relay becomes operated and places a ground on conductor 30 which iscommunicated in parallel to each of the relays 5, 6 and 7 and to signallamp 31. The design and adjustment of relays 21, 23 and 25 is such thatthe rate of operation of relay 29 and consequently the periodicapplication of ground to conductor 30 is the same as the rate ofinterrupter 1.

Now since the distributing circuit 4 is permanently grounded at thefront contact of relay 3, each of the signaling circuits 8, 9 and willbe grounded during the deenergization of relays 5, 6 and 7 and theresult is that the signaling circuits are intermittently grounded asbefore.

It should be noted that now even though a particular signaling circuitsuch as 8 becomes permanently grounded, that this ground cannot becommunicated to the other signaling circuits during the operation of theemergency interrupter circuit comprising relays 21, 23, 25, 27, 28 and29.

An attendant noting the steady illumination of signal 19, theintermittent illumination of signal 31, and the alarm 18, may bypressing key 17, restore the circuit to normal by allowing relay 16 tobecome deenergized. If the trouble which occurred was of atemporarynature and has been righted by this time, relay will be in itsenergized condition and when key 17 is pressed, the circuit will assumeits normal condition and begin to operate properly. If, however, thecircuit is of a more permanent nature, then when the key 17 is restored,the alarm 18 and the signals 19 and 31 will again operate and thetrouble will.

have to be traced and properly adjusted. When the trouble is cleared,the circuit may then be restored to normal by a momentary depression ofkey 17.

What is claimed is:

1. In a signaling system, a plurality of electric signal devices eachhaving two terminals, means for connecting a source of operating currentto one terminal of any one device, a plurality of signal conductorsindividually connected to the free terminals of said devices, aninterrupter lead, an interrupter adapted to periodically connect groundthereto, a permanently grounded lead, a multi-contact relay normallyconnecting all of said signal conductors to said interrupter lead, meansfor periodically operating said relay, other means responsive to asteady ground condition on said interrupter lead for disconnecting saidinterrupter lead from the contacts of said relay and substituting forsaid interrupter lead said other permanently grounded lead and forinitiating the operation of. said means for periodically operating saidrelay to periodically disconnect said permanently grounded lead fromsaid signal conductors.

2. In a signaling system, a common lead, (4), a plurality of individualload conductors (8, 9, etc), signaling devices associated therewith andadapted to be operated thereover, an interrupter lead (2), means (1)associated'therewith for intermittently connecting ground thereto, means(3) normallyconnecting saidcommon lead (4) to said interrupter lead (2)and adapted to be actuated to disconnect said interrupter lead (2) fromsaid common lead (4) and to connect a steady ground to said common lead(4) a multicontact relay (5) normally connecting said common lead (4) tosaid load conductors (8, 9, etc.) in multiple, auxiliary means (21, 23,25, 27, 28

and 29) for intermittently'operating said multicontact relay (5), relaymeans (16) responsive to a ground condition on said interrupter lead (2)for a, predetermined period longer than the ground conditionintermittently applied thereto by said first means (1). to actuate saidsecond means (3) and to initiate the operation of said auxiliary means(21, 23, 25, 2'7, 28 and 29).

7 JOHN B. SHIEL.

ALBERT G. LANG.

